• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.5
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• pp.725-730
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• 2010

The differences between organic and conventional rice were studied from the point of view of quality, physiochemical property and functionality. It was concluded that organic rice showed a 6% lower complete rice ratio than conventional rice. However, organic rice exhibited more excellent physiochemical property on amylose or protein content, Toyo value, and acidity with 17.5%, 6.6%, 8.12%, and 8.7%, respectively. There was no difference between two kinds of rice on alkali digestion value and amino acids contents such as Asp, Ser, Glu, Ala, Leu, Arg. Among inorganic compounds of rice, four compounds including B, Mn, Fe, or Zn were slightly higher at organic rice with 1.1~2.7 mg/100 g, compared to conventional rice. Interestingly, total phenolic acid and phytic acid content were 89% or 23% higher at organic rice than conventional rice, respectively. MeOH extract from organic rice showed higher antioxidant activity with 26% than that of conventional rice with 22%. In contrast, conventional rice was favored than organic rice on stickness, taste, palatability fields at sensory evaluation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.7
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• pp.624-631
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• 2006

This study was conducted to make clustering analysis based on major physicochemical characteristics related to palatability of cooked rice. 89 Korea-bred japonica rice cultivars could be largely classified into two groups, that is, Dongjinbyeo and Ilpumbyeo groups. The Ilpumbyeo group was divided into two subgroups; Ilpumbyeo and Chucheongbyeo groups. The two major rice groups showed significant difference in viscogram properties of rice flour. Ilpumbyeo group revealed slightly higher estimates of viscogram traits as compared with Dongiinbyeo group in average. Early-maturing rice group showed slighly lower estimates of taste meter and higher protein content compared with medium or medium late maturing ones. Also, early and medium-maturing groups exhibited slightly higher estimates of peak, hot and breakdown viscosities but lower estimates of consistenency and setback viscosities compared with medium-late-maturing one. The rice cultivars developed in 2000's revealed slightly higher estimates of peak, hot, cool and consistency viscosities compared with those in $1980's{\sim}1990's$. The grain quality properties significantly associated with the esimates of Toyo taste meter were protein and amylose contents and hot viscosity. The lower protein content and hot viscosity and the higher amylose content, the higher estimates of the taster meter. The protein content was highly negatively correlated with amylose content of milled rice. The important quality components contributed to multiple regression formula for estimating the Toyo taster meter values were protein content, alkali digestion value, and hot viscosity. The fittness of this formula was about 49% along with the coefficients of determination.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.3
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• pp.408-414
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• 2011

The purpose of this study was to find out optimum cultivated regions for rice organic farming. The organic and conventional rice as control were grown in three different places : secluded hill paddy field for Hapcheon, normal rural paddy field for Sancheong, and suburban paddy field for Jinju from 2005 to 2006. In secluded hill paddy field, the organic material and pesticide to control pest and disease were input twice for organic and conventional rice cultivation. However, in normal rural and suburban paddy field, those were input three times for organic and conventional rice cultivation. The occurrence of sheath blight in organic farming was higher than in conventional farming. Whereas brown planthopper population per 20 plant was significantly high 10.1~19.5 for conventional farming compared with 4.4~10.0 for organic farming. For that reason, the density of the brown planthoppers was higher in organic farming than those in conventional farming. Dominated weeds occurred in organic and conventional paddy field were namely Monochoria vaginalis, Ludwigia prostrata, and Cyperus difformis. The population per 20 plant and dried weight per $m^2$ of weeds were higher in 121 and 50.5 g for organic paddy field. The productivity of rice in different cultivated regions for organic farming was $2.96Mg\;ha^{-1}$ in hill paddy field, $4.03Mg\;ha^{-1}$ in normal rural and suburban paddy field. Toyo-taste value and ratio of perfect grain of milled rice were not different by cultivated regions in both farming system.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.5
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• pp.296-305
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• 2002

Rice yield and grain guality were investigated with treatments of silicate fertilizer, straw compost and NPK fertilizer in the paddy soil of silty clay loam from 1975 to 2001. Rice yield of the treatments of silicate fertilizer. $1,500kg\;ha^{-1}$ and straw compost $10,00kg\;ha^{-1}$ were increased by 15%, 10%, respectively, for 27years average yield in comparison with NPK plot. In the plots of NPK+silicate fertilizer $1,500kg\;ha^{-1}$, NPK+silicate fertilizer $2,500kg\;ha^{-1}$, taste value(Toyo instrument) of cooked rice and quality assessment were higher than those in NPK control plot and NPK+straw compost $10,000kg\;ha^{-1}$ plot, but the contents of crude protein, amylose of milled rice grain were lower than those in other treated plots. Nitrogen and phosphorous contents of rice plant were lower, but $SiO_2$ content were higher in the treatment of silicate ferti lizer 1,500, $2,500kg\;ha^{-1}$ than straw compost $10,000kg\;ha^{-1}$ plot. Rice quality assessment was positively correlated with taste value, but it was negatively correlated with crude protein and amylose content of milled rice grain. Ratios of Mg/N, $Mg/N{\cdot}K_2O$, $SiO_2/N$, $SiO_2/P_2O_5$ and $SiO_2/K_2O$ were positively correlated with taste value and quality assessment of rice grain, but negatively correlated with crude protein, amylose and fatty acid content. In soil chemical characteristics related with rice quality after experiment in 2001, soil pH and $SiO_2$ content were positively correlated with taste value and quality assessment of rice grain, but contents of soil $P_2O_5$, ex-K were negatively correlated with them.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.3
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• pp.301-309
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• 2012

This study was performed to compare the properties affecting the palatability of 33 commercial brands of rice. Five rice varieties were identified including Chucheongbyeo, Hitomebore, Ilpumbyeo, Nampyeongbyeo, Seachucheongbyeo, were compared in terms of physicochemical characteristics, texture, head riceratio, and palatability through Toyo values. We also analyzed the relationship between grain characteristics and palatability. Amylose content of 5 rice varieties ranged from 17.04-17.98%. Nampyeongbyeo had the lowest and Seachucheongbyeo had the highest content of amylose among rice varieties. The protein content of 5 varieties ranged from 6.72-7.55%. Nampyeongbyeo showed the highest content. The moisture content varied from 13.08-14.83%. Chucheongbyeo has the highest moisture content. The head rice ratio of Ilpumbyeo, Chucheongbyeo, and Seachucheongbyeo were over the 90%, which was lower than that of Japan. Chucheongbyeo had the lowest hardness value and the highest adhesiveness value as measured by texture analyzer. The palatability value was highest in Chucheongbyeo, and the lowest in both Nampyeongbyeo and Ilpumbyeo. The palatability value was negatively correlated with protein content, but positively correlated with texture, moisture content, and head rice ratio. Based on this results, the rice varieties with high palatability had lower contents of amylose and protein, but higher moisture content and head rice ratio. Chucheongbyeo seemed to be the valuable variety with the highest palatability among them.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.9
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• pp.1313-1319
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• 2010

Rice cultivars of Goami2 (G2), Baegjinju (BJJ), and Sulgaeng (SG) with different amylose contents were developed by mutation breeding via N-methyl-N-nitrosourea (MNU) treatment to Ilpumbyeo (IP), high japonica rice. They were identified by different appearances such as grain size, color, and shape. In this experiment, the compositional and physical qualities of those cultivars were examined. The G2 rice classified as a high-amylose rice cultivar was significantly higher in its non-digestable carbohydrates contents. Linoleic and oleic acid were composed of 70~75% of all fatty acids composition regardless of milled and brown rice, except G2 rice in which palmitic acid was the major fatty acid followed by linoleic acid and oleic acid in order. Major amino acids were aspartic acid, glutamic acid, and hydroxy lysine. It was found that cysteine contents were higher in the cultivars of endosperm mutant rice. The DSC analysis revealed that enthalpy was the highest in BJJ followed by SG, IP, and G2 rice. The lowest enthalpy of G2 might be attributable to the higher amylose content. Ilpumbyeo in its cooked rice form showed the highest in Toyo value and less in hardness, but G2 was vise versa. Results of gelatinization and cooked rice properties suggest that G2 was less suitable for cooked rice, but has a potential for functional ingredients from nutritional point of view. The BJJ and SG could be used for traditional cooking as well as for processed foods.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.3
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• pp.227-232
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• 2006

Rice quality must certainly be considered as one of the primary preference for consumers. On aspect concerns marketing, such attributes as appearance, physicochemical characteristics, and palatability of brand rice are very important. Therefore this study was carried out to observe the quality of commercial brand rice in Gyeongbuk Province, Korea from 2002 to 2004. In seasonal changes of mean air temperature from early July to middle August, it was lower in 2003 by $0.8{\sim}3.3^{\circ}C$ than that in normal year. Among the rice quality characteristics, the cv of percentage of head rice and palatability (Toyo value) were very low but those of chalky rice and protein content were very high during three years, and the same tendency was also observed among the brands. The average percentages of head rice were 92.5% in 2002, 89.9% in 2003 and 93.3% in 2004, respectively. On the contrary, the percentages of chalky rice were higher in 2003 as 4.9% than those in 2002 (3.9%) and in 2004 (2.8%). These results were caused by the abnormal meteorological conditions in 2003. Due to the higher protein content (8.0%) in 2003, the palatability was deteriorated to 71.0. However the protein content in 2004 was reduced to 7.0% and this result improved the palatability to 77.0.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.254-254
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• 2017

This study evaluated the grain quality of local brand rice from 6 major rice exporting countries which are anticipated to export their rice to Korea. Recently, with the end of the postponement of rice import tariffs in 2014, Korea is in a very easy environment to import foreign rice. Therefore, the quality evaluation of local brand rice in those countries is needed to secure the quality competitiveness of Korean rice, also to protect the rice industry in Korea. We provided total 38 local brand rice from USA(7), China(16), Australia(4), Thailand(3), Vietnam(5) and India(3), and 2 imported brand rice through MMA from USA and China to find out the status of the grain quality for each country. For the quality evaluation, we analyzed the physicochemical properties, milling and palatability-related characteristics. The amylose content on country average ranged from 24.4(India)~16.2%(Thailand). The protein content was 6.66% by overall average, and was higher in order of India(7.86), Australia(6.80), Vietnam(6.61), Thailand(6.59), China(6.28), USA(5.82). In Toyo glossiness value, it ranged from 75.7~45.2, and the figures in USA and China were the highest level. The head rice ratio ranged from 95.2~72.4%, and the figures in Thailand, USA and China were distinctly high. When we analyze the palatability of boiled brand rice with Chucheongbyeo as check variety by expert panelists, several rice brands from USA and China showed equal or better scores in shape, smell, taste, stickiness, texture and overall score, although most rice brands showed a tendency to decrease significantly in the taste characteristics compared with Chucheongbyeo. From the above results, it can be seen that the grain quality of USA and China rice is very competitive when imported into Korea. The results will provide basic information for the quality control of foreign rice which will be imported into Korea in the near future, also for the quality information which could be applied on the development of high-quality Korean rice varieties. Continuous monitoring about the foreign brand rice is advisable to improve the quality competitiveness of Korean rice.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.69-69
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• 2017

Due to the lack in storage facility, considerable amount of rice is stocked in the open air, which causes increased stale flavor and deteriorates palatability and merchantable quality. Lipoxygenase-3(LOX-3) is involved in the production of volatile constituents in stored rice, and the development of stale flavor is delayed in LOX-3 null rice. LOX activity in the rice grain is localized in bran fraction and the tropical Japonica cultivar 'Dawdam' was reported that the absence of LOX-3 is inherited as a simple recessive trait. Also, it was reported that the peroxidation of unsaturated fatty acids occurs at lower levels in the 'Dawdam' bran fraction during storage than in rice varieties with LOX-3. This study was conducted to develop LOX-3 null rice lines using 'Dawdam' and investigate changes of physicochemical properties of the lines stored at different storage temperatures and periods. So we analyzed texture, toyo glossiness value, germination rate and lipoxygenase activity of 15 LOX-3 null rice lines on the condition of which rough rice had been stored at different temperatures (high temperature condition at $35^{\circ}C$ and low temperature condition at $15^{\circ}C$ for 4months. Hardness and stickiness of the lines tendered to be increased when it was stored at high temperature and adhesiveness, springiness, cohesiveness and chewiness was not considerably different according to storage temperatures and periods. The germination rate of HR29062-B-98-2-1-B among LOX-3 null rice lines was higher than another lines, 99.3, 94.0% after 4months stored at low temperature and high temperature, respectively. The lipoxygenase activity was 3,304, 1,601unit/mg protein after 4months stored at low temperature and high temperatures, respectively. So, it is thought that this line will be useful to breed rice varieties with high storability after tested on agricultural traits.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.2
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• pp.86-94
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• 2006

The primary concern on fertilizer recommendations on paddy soils in Korea is not high rice yield but high rice quality, sustainable rice yield, and less environmental loads these days. Based on soil survey data, the paddy soils in Korea were classified into five large management types ; normal, sandy, immatured, poorly drained, saline soil. In order to establish the optimum level of nitrogen fertilizer to increase the rate of head rice yield, field experiments were conducted at 24 farmhouses throughout the country with nitrogen fertilizer treatment levels of 0, 50, 70, 90, 110, 140, $170kg\;ha^{-1}$ from 2003 to 2004. As the result of the experiment, the optimum rates of nitrogen fertilizer for improving rice quality were $90kg\;ha^{-1}$ in normal, sandy, and poorly drained soils, $100kg\;ha^{-1}$ in immatured soils, and $112kg\;ha^{-1}$ in saline soils where the content of NaCl in soil was below 0.1%. The optimum rates of nitrogen fertilizer were determined in view of head rice percent, protein content, and palatability value of rice.